Browsing School of Engineering & Computer Science by Issue Date
Now showing 1 - 20 of 299
Results Per Page
ItemEvolving a disjunctive predator prey swarm using PSO : adapting swarms with swarms.(2006-02-15T15:56:04Z) Riyaz, Firasath; Maurer, Peter M.; Marks, Robert J., II (Robert Jackson), 1950-; Computer Science.; Baylor University. Dept. of Computer Science.Swarm Intelligence is the study of "the emergent collective intelligence of groups of simple agents." Recent research has explored the important applications in the field of business, telecommunications, robotics and optimization. This thesis models a simple prey swarm disjunctively, i.e. a number of disjoint survival attributes are aggregated into a single response. The swarm was initialized using heuristics. We studied the ability of this swarm to evolve its performance using a particle swarm optimization on the disjunctive rules. The rules are characterized through use of a fuzzy inference engine and the rules adapted through changing of the rule membership functions. The result was both improved performance and unexpected emergent behavior for example individual members of the prey swarm began to sacrifice their life to lengthen the life of the swarm aggregate. The disjunctive swarm is found to be robust against rule failures. ItemData compression application to the MIL-STD 1553 avionics data bus.(2006-05-11T16:11:15Z) Weston, Bron O.; Duren, Russell Walker.; Thompson, Michael Wayne.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.With the current state of legacy military avionic systems reaching its ceiling in memory space, processing power, and data-bus through-put (bandwidth), a need has arisen to maximize its limited resources to avoid extensive costs of system overhaul. Specifically, F/A-18 C/D Aircraft is approaching message capacity on its MIL-STD-1553 buses. To slow this assent to capacity limits, one possible solution implements data compression techniques to increase bandwidth. In these efforts, this thesis examines different lossless compression schemes to find ideal options to consider for implementation on MIL-STD-1553 based F/A-18 C/D Aircraft. Several compression routines are identified that provide significant data compression while requiring very little computational effort. A surprising benefit is that the reduction in wasted time spent waiting on data communication more than offsets the time required to compress and decompress the data. ItemJava bytecode compilation for high-performance, platform-independent logical inference.(2006-05-11T16:38:51Z) Arte, Ashish.; Sturgill, David Brian.; Computer Science.; Baylor University. Dept. of Computer Science.Automated reasoning systems are powerful computer programs capable of solving complex problems. They are characterized as computationally intensive having high performance requirements. Very few reasoning systems have been implemented in Java so far; its performance is regarded as an impediment to its use as a programming language for computationally intensive applications such as automated reasoning. In this thesis we discuss techniques that motivate the use of Java as the underlying platform to design a framework for high-performance logical inference. The techniques are centered around the idea of using a specialized compiler that can generate Java classes which contain Java bytecodes customized for performing reasoning efficiently. The benefit of generating bytecodes customized for logical inference is reflected in the improved performance observed from the experiments conducted. ItemThe influence of load on kinematics of computer-simulated sagittal-plane lifting.(2006-05-11T17:03:31Z) Newman, Patrick S.; Garner, Brian Alan, 1966-; Mechanical Engineering.; Baylor University. Dept. of Mechanical Engineering.Researchers have shown that lifting kinematics change predictably with increased load. To test whether these kinematics patterns are intrinsic or voluntary, a computer model was developed to simulate lifting in the sagittal plane. The eight-degree-of-freedom model included the ankle, knee, hip, shoulder, elbow, neck, and two back joints. Strength limits were assigned to model joints according to position-dependent average male data obtained from the literature. Using both forward and inverse dynamics approaches, the model was programmed to lift various loads while tracking lift kinematics measured from a human subject. Simulation results suggest that, contrary to common hypotheses, observed lifting patterns are not dictated by physical law (intrinsic) but are chosen for efficiency and stability (voluntary). In this study, a method for isolating kinematic dependencies is introduced. It is anticipated that the results will help in the understanding of motion perception, lifting technique, and low-back pain. ItemDevelopment and implementation of real-time distributed network with the CAN protocol.(2006-05-27T13:44:18Z) Ford, Walter Davis; Gravagne, Ian A.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.One of the most interesting applications of a new field of mathematics called dynamic equations on time scales is the modeling, analysis and design of distributed control networks. This thesis documents the development of a scalable, real-time test bed on which to test new time scale-based theories. The Controller Area Network (CAN) protocol is used as the communication backbone. A general description of CAN and reasons for its selection are included. A general purpose computational node is implemented on a desktop computer running the QNX real-time operating system. QNX development entailed writing a driver for an SJA1000-based CAN controller. Charmed Labs’ Xport and the Gameboy Advance (GBA) are used for the network of embedded nodes. Development for the GBA-Xport combination involved interfacing an OpenCores.org CAN core to the Xport’s bus on an FPGA in Verilog and writing a driver class. Appendices include the code and code documentation. ItemDesign of a microwave sensor for non-invasive determination of blood-glucose concentration.(2006-05-27T14:46:59Z) Green, Eric C.; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Diabetes is a disease that afflicts millions worldwide. To control the effects of this disease, diabetics must check their blood glucose levels on a regular basis. Currently, all daily glucose monitoring techniques are invasive, requiring a sample of blood. Microwave sensors are non-destructive and non-contact measuring devices, making them ideal for the measurement of parameters in industrial processes. Current uses of microwave sensors range from measuring moisture content of corn chips to measuring concentration of a solute in water. If a microwave sensor were developed to determine blood glucose concentration, it could be the first daily-use glucose-measuring technique that is truly non-invasive. This thesis provides background on diabetes and microwave measurement. From this background, a sensor is developed and its advantages are illustrated. The thesis concludes by making suggestions for improving the sensor and recommendations on how to implement the sensor into a useful product. ItemThe design and validation of an impinging jet test facility.(2006-05-28T01:13:46Z) Robertson, Peter R.; Van Treuren, Kenneth W.; Mechanical Engineering.; Baylor University. Dept. of Mechanical Engineering.An experimental jet impingement facility was constructed with the capability of conducting a detailed analysis of the local heat transfer coefficients beneath an array of large impinging jets. The facility was validated with initial heat transfer studies that determined an appropriate jet discharge coefficient of 0.802 and created a correlation relating local jet Reynolds number and stagnation point heat transfer. The correlation matched closely with previous studies. The thermal effects of impinging jets were visualized by liquid crystal thermography. The resulting thermal footprints of downstream jets revealed the first known documented case of the heat transfer effects of horseshoe vortices on the target surface. This phenomenon was identified and discussed. ItemAnalysis of transaction throughput in P2P environments.(2006-05-28T01:24:49Z) Chokkalingam, Arun.; Speegle, Gregory David.; Donahoo, Michael J.; Gipson, Stephen L. (Stephen Lloyd); Green, Gina C., 1962-; Computer Science.; Baylor University. Dept. of Computer Science.In recent years P2P systems have gained tremendous popularity. Support of a transaction processing facility in P2P systems would provide databases at a low cost. Extending distributed database algorithms such as 2PC and ROWA to P2P environments might not provide the best performance because the P2P systems are characterized by high site failure rates and an unpredictable network topology. The choice of algorithms in building P2PDB is difficult because of the lack of information about the performance of database algorithms in P2P environments. This thesis analyzes the performance of one such algorithm, the epidemic algorithm against the performance of traditional database algorithms in simulated P2P environments. ItemA new modality for microwave tomographic maging: transit time tomography.(2006-07-22T22:45:56Z) Trumbo, Matthew Lee.; Marks, Robert J., II (Robert Jackson), 1950-; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.A new method for tomographic imaging using time delay of microwaves as they pass through objects of varying dielectric is presented. To obtain this delay measurement, recording of transmitted waveforms is performed when broadband microwave signals are sent through objects. The experimental setup consists of a circular table with vertically polarized bi-conic horns as transmitting and receiving antennas, with a Vector Network Analyzer as the excitation and measurement device. By obtaining multiple point tomographic projections at multiple angles, a reconstruction of the classic X-ray Radon transform is possible. Results obtained show accuracy and resolution limits to be within acceptable ranges and offer many new, less expensive possibilities for tomographic imaging. ItemA comparison of field programmable gate arrays and digital signal processors in acoustic array processing.(2006-07-29T16:28:42Z) Stevenson, Jeremy C.; Duren, Russell Walker.; Thompson, Michael Wayne.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.The Field Programmable Gate Array's (FPGA) constant growth in computing power has given embedded system developers a choice to replace their current processors with a FPGA. However, most systems continue to use the original processor due to familiarity and design speed. Design tools, such as Simulink for MATLAB, have created a potential for significantly reducing FPGA development time. This potential was explored by developing an acoustic array processing system on both a FPGA and a DSP (Digital Signal Processor). The system includes a filtering stage, a correlation stage, and a trigonometric math stage. All of these stages are computationally intensive which provide an accurate portrayal of the chips' capabilities. The paper documents the comparison of the FPGA and the DSP implementations in regards to the performance of each implementation, the design time of each implementation and the capability of the design tools used in each implementation. ItemDetermining the complex permittivity of materials with the Waveguide-Cutoff method.(2006-07-31) Anderson, Christopher.; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.A new method for the determination of complex permittivity values is explained. The Waveguide-Cutoff method consists of a rectangular chamber with loop antennas for excitation from a Vector Network Analyzer. It then utilizes a particle swarm optimization routine to determine Debye parameters for a given material within the sample. The system is compared to a common Open-Ended Coaxial Probe technique and found to have similar accuracy for determining the dielectric constant over the same frequency band. This syste, however, does not suffer from the same restrictions as the coaxial probe and has a much larger bandwidth than other transmission line methods of similar size. ItemPG-means: learning the number of clusters in data.(2007-03-19T14:52:48Z) Feng, Yu.; Hamerly, Gregory James, 1977-; Computer Science.; Baylor University. Dept. of Computer Science.We present a novel algorithm called PG-means in this thesis. This algorithm is able to determine the number of clusters in a classical Gaussian mixture model automatically. PG-means uses efficient statistical hypothesis tests on one-dimensional projections of the data and model to determine if the examples are well represented by the model. In so doing, we apply a statistical test to the entire model at once, not just on a per-cluster basis. We show that this method works well in difficult cases such as overlapping clusters, eccentric clusters and high dimensional clusters. PG-means also works well on non-Gaussian clusters and many true clusters. Further, the new approach provides a much more stable estimate of the number of clusters than current methods. ItemPrincipal component and neural network calibration of a microwave frequency composition measurement sensor.(2008-03-03T17:17:16Z) Maule, Charles Stephen.; Marks, Robert J., II (Robert Jackson), 1950-; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Microwave sensors are becoming more prevalent throughout a variety of industries. While providing an effective form of measurement, microwave sensors are difficult to calibrate and provide results which can be difficult to interpret. An improved method for calibrating microwave sensors has been developed which transforms the waveform of a microwave spectrometer using principal component analysis and the results are used to train an artificial neural network to analyze a subject material. Broadband microwave spectrum calibration (BBMSC) is demonstrated using waveforms captured by a microwave spectrometer in a circular waveguide containing pulp stock slurry. This thesis provides a review of the general applications of microwave sensors, details state-of-the-art calibration methods, as well as providing an introduction to principal component analysis and neural networks. The thesis continues by presenting the BBMSC method in detail, as well as how this method is applied to a set of waveforms of pulp-stock data and concludes with a discussion of the potency of BBMSC and recommendations for the future. ItemExperimental investigation of a time scales linear feedback control theorem.(2008-03-03T17:25:15Z) Allen, Benjamin T.; Gravagne, Ian A.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Dynamic equations on time scales comprise an exciting new area of research in mathematics which promises applications in many areas, particularly control theory. This thesis describes the design and implementation of a simulator and real-time controller useful for experimentation with and demonstration of the applications of time scale control theory. Under the guidance of the Baylor time scales group, the system is used to test a time scales feedback control equation currently under research. ItemCalibration methodology for a microwave non-invasive glucose sensor.(2008-06-09T15:41:02Z) McClung, Melanie J.; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Non-invasive measuring techniques for determining biological parameters are more heavily researched with the growth of the biomedical industry. One of the top areas in non-invasive research deals with diabetes. This disease affects more than 20 million people in the United States, and there is an increasing desire to find a testing process that is non-invasive, easy to use, and safe for users. Microwave technology has improved greatly during recent years and is now seen more often in conjunction with biomedical research. Microwaves are capable of taking measurements of materials inside of a closed volume without the need to come into contact with the material. This makes them ideal for measuring biological parameters, specifically glucose concentrations in the blood. This thesis expands on the development of a microwave sensor to non-invasively measure blood glucose levels and will examine the possibility of developing a calibration for a device using the microwave sensor. Item"Two-way" obliviousness in general aspect-oriented modeling.(2008-10-01T16:55:12Z) Roberts, Nathan V.; Song, Eunjee.; Computer Science.; Baylor University. Dept. of Computer Science.A key problem in software development is producing systems that are maintainable even as the concerns at play evolve. Aspect-oriented programming (AOP) seeks to foster maintainability by isolating the speciﬁcations of cross-cutting concerns, allowing them to be modiﬁed in relative isolation from the rest of the system. Research in aspect-oriented modeling (AOM) aims to develop a model-layer analogue of AOP, allowing integration with accepted modeling practices. Aspects usually allow developers of the primary model to be oblivious to the aspects that modify the primary model; because of this, aspects can be closely coupled to potentially transient details of the primary model. When those details change, the aspects that depend on them may no longer have the desired eﬀect. In this thesis, we examine three approaches to AOM, and introduce a novel solution to the problem of obliviousness by extending a graph-transformational approach to AOM. ItemA linked-plane obstacle-set algorithm for modeling broad muscle paths : application to the deltoid muscle.(2008-10-01T19:03:48Z) Xu, Bo, 1984-; Garner, Brian Alan, 1966-; Engineering.; Baylor University. Dept. of Mechanical Engineering.Computer modeling is commonly used to simulate muscle paths for the study of human biomechanics. Because some muscles, such as broad muscles, have complex morphology, modeling the paths of these muscles can be challenging. The aim of this study is to develop a new algorithm that quickly and realistically models the wrapping paths of broad muscles. The algorithm treats the muscle as a series of elastic bands wrapping around sphere-shaped obstacles. Each band is constrained to lie in its own plane and wrap around its own sphere. Each band plane forms a given angle with respect to the adjacent band plane, with the first band plane forming an optimized angle with respect to a fixed reference plane. The optimization seeks to minimize the sum total of all band lengths. The new algorithm accounts for tissue connectivity between muscle fibers in broad muscles, and can reproduce realistic muscle moment arm simulations. ItemAn evaluation of CoWare Inc.'s Processor Designer tool suite for the design of embedded processors.(2008-12-01T16:28:01Z) Franz, Jonathan D.; Duren, Russell Walker.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.The goal of this thesis is to evaluate the Processor Designer family of tools from CoWare, Inc. Processor Designer uses the L.I.S.A. 2.0 (Language for Instruction Set Architecture) language. The evaluation is being performed to determine the suitability of the toolset for incorporation into a classroom environment and for the use in developing replacements for legacy processors. The main focus will be on the ease of use of the tools. This includes exploring how steep of a learning curve is involved with this new processor designer language and how well the tools have been documented. The limitations of the tools will also be explored, as far as what can and cannot be done in the language. The thesis is also intended to provide a tutorial introduction to the CoWare Inc. tool suite for future students. ItemUsing GF(2) matrices in Simulation and Logic Synthesis(2009-01-23T16:31:18Z) Maurer, Peter M.GF(2) matrices are matrices of ones and zeros under modulo 2 arithmetic. Like the GF(2) polynomials used in error detection and correction, they have many potential uses in Electronic Design Automation (EDA). Non-singular matrices can be used to define new classes of symmetry called conjugate symmetries. Conjugate symmetries have been used to speed up certain kinds of functional-level simulations, and have other potential uses. GF(2) matrices can also be used to transform Boolean vector spaces and simplify Boolean functions. Although matrix transformations can be complex, simpler single-bit matrices can be used instead of general matrices. This simplifies the approach without loss of generality. Singular matrices can be used to reduce the complexity of certain functions, beyond what is normally possible with conventional simplification techniques. GF(2) matrices can also be used to define exotic symmetries called strange symmetries and collapsed symmetries. These exotic symmetries may prove useful in future EDA applications. ItemUsing GF2 Matrices to Simplify Boolean Logic(2009-01-23T19:40:41Z) Maurer, Peter M.Conventional logic simplification can be couched in terms of singular GF(2) matrices. The advantage to doing this is that different matrices can be used to combine terms that are separated by a Hamming distance greater than one. Although this sort of thing can be done without matrices, it is not clear what one would do after finding such terms. We show that by applying a matrix transformation to the inputs of a function, we can combine terms that are at arbitrary distances. We also show that we can further simplify functions by transforming the input vector space with a non-singular transformation.